Applications Information

Power-Supply Sequencing

and Overvoltage Protection

Do not exceed the absolute maximum ratings, because

stresses beyond the listed ratings may cause perma-

nent damage to the devices.

Proper power-supply sequencing is recommended for

all CMOS devices. Always apply V+ before applying

analog signals or logic inputs, especially if the analog

or logic signals are not current limited. If this sequenc-

ing is not possible, and if the analog or logic inputs are

not current limited to 20mA, add a small-signal diode

(D1) as shown in Figure 1. If the analog signal can dip

below GND, add D2. Adding protection diodes

reduces the analog signal range to a diode drop (about

0.7V) below V+ (for D1), and to a diode drop above

ground (for D2). Leakage is unaffected by adding the

diodes. On-resistance increases by a small amount at

low supply voltages. Maximum supply voltage (V+)

must not exceed 13V.

Adding protection diodes causes the logic thresholds

to be shifted relative to the power-supply rails. This can

be significant when low supply voltages (+5V or less)

are used. With a +5V supply, TTL compatibility is not

guaranteed when protection diodes are added. Driving

IN1 and IN2 all the way to the supply rails (i.e., to a

diode drop higher than the V+ pin, or to a diode drop

lower than the GND pin) is always acceptable.

Low-Voltage, Quad, SPST

CMOS Analog Switches

_______________________________________________________________________________________

7

POSITIVE SUPPLY

COM_

NO_

Vg

V+

MAX4610

MAX4611

MAX4612

Figure 1. Overvoltage Protection Using Two External Blocking

Diodes

Pin Description

PIN

MAX4610

MAX4611

MAX4612

TSSOP/SO/ DIP

QFN

TSSOP/SO/DIP

QFN

TSSOP/SO/DIP

QFN

NAME

FUNCTION

1, 3, 8, 11

1, 3,

8, 11

———

—

NO1–NO4

Analog Switch Normally Open

Terminals

——

1, 3, 8, 11

1, 3,

8, 11

——

NC1–NC4

Analog Switch Normally Closed

Terminals

——

—

—

1, 8

1, 8

NO1, NO3

Analog Switch Normally Open

Terminals

——

—

—

3, 11

3, 11

NC2, NC4

Analog Switch Normally Closed

Terminals

2, 4, 9, 10

2, 4,

9, 10

2, 4, 9, 10

2, 4,

9, 10

2, 4, 9, 10

2, 4,

9, 10

COM1–COM4

Analog Switch Common

Terminals

13, 5, 6, 12

14, 5,

6, 13

13, 5, 6, 12

14, 5,

6, 13

13, 5, 6, 12

14, 5,

6, 13

IN1–IN4

Logic-Control Digital Input

7

7

7

7

7

7

GND

Ground. Connect to digital

ground.

—

12, 15

—

12, 15

—

12, 15

N.C.

No Connection. Not internally

connected.

14

16

14

16

14

16

V+

Positive Analog and Digital-

Supply Voltage Input. Internally

connected to substrate.